Over the years, basic plumbing systems used for delivering potable water have evolved so that the plumbing systems can be more easily repaired with less manpower and at reduced costs. Not only have materials improved, but also the components making up plumbing systems have advanced so that plumbing systems are also more reliable. Although basic plumbing systems in the home or business can be fairly characterized as simple mechanical systems, there is still much room for improvement in further reducing the costs of such systems as well as simplifying their construction.
One aspect of common plumbing systems which has not changed over the years is the means by which faucet knobs or handles are attached to the valve stems of valve assemblies which control the flow of water. The great majority of all faucet handles are attached to their valve stems by means of a threaded screw which mates with a tapped portion of the valve stem shaft or a tapped insert connected to the valve stem shaft. To conceal the threaded screw for decorative purposes, most such handles must be specially constructed to include a recessed portion which receives an index cap or cover to conceal the threaded screw. The special construction of the handle requiring an index cap along with the use of a threaded screw and a threaded valve stem shaft/insert all add to the cost of a faucet assembly. Furthermore, since the connection between the index cap and the handle is not watertight, moisture can be introduced into the recess and to the threaded screw causing corrosion. The corrosion can make it difficult to remove the set screw, and the index cap can become lost, broken, or lose its capability to properly attach to the handle. The connection can also be the means by which bacteria and other undesirable microorganisms can grow because of the trapped moisture, thus making the handle a possible source of contamination after one has washed his/her hands.
Each of the foregoing disadvantages can be overcome by the use of a knob or handle which may simply friction-fit over a valve stem shaft. In other words, the use of a compression-type fitting for connecting the handle to the valve stem shaft eliminates the need for a threaded screw, an index cap, and a recess in the knob or handle to receive the index cap.